Federal prosecutors urged a judge Wednesday not to strike key portions of testimony by Andy Pettitte in the perjury trial of Roger Clemens, arguing that jurors should be permitted to weigh the value of his various statements.

In a 15-page legal brief, prosecutors opposed a defense motion to block jurors from considering Pettitte’s testimony last week that Clemens confided in him in 1999 or 2000 that he had taken the performance-enhancing drug Human Growth Hormone (HGH), and it helped him recover, presumably from injuries and intense workouts.

Pettitte made that statement while being questioned by prosecutors. On cross-examination, however, Pettitte was more equivocal.

He agreed that there was a “fifty-fifty” chance he had misheard his friend back in 1999 or 2000. Defense lawyers then asked U.S. District Judge Reggie B. Walton to strike Pettitte’s testimony about HGH because it had the “weight of a coin flip.”

Pettitte’s testimony is considered critical to the government’s case because he was a good friend of the star pitcher and had nothing to gain by testifying against him. Clemens is accused of lying to Congress in 2008 when he denied ever having taken steroids or growth hormone.

In their own legal filing, prosecutors countered that “this jury must be permitted – if it desires – to fully credit Mr. Pettitte’s direct-examination testimony and discount any cross-examination inconsistencies.”

They wrote that they revisited the issue with Pettitte before he left the witness stand when they showed him a chart listing his various conversations with Clemens about performance-enhancing drugs over the years.

The chart described the 1999 or 2000 conversation this way: “RC used HGH & it helped with recovery.”

“The chart that you have here, Government’s Exhibit 45, is this true and accurate to the best of your knowledge,” Assistant U.S. Attorney Steven Durham asked him.

“Yes, sir, to the best of my knowledge.”

“That testimony thus dispelled any lingering ambiguity about Mr. Pettitte’s understanding of the content of defendant’s admission,” prosecutors wrote in their court filing.

Prosecutors conceded that drawing such a conclusion would require someone to draw “reasonable inferences” from testimony elicited from the exhibit.

Last week, Walton seemed to lean in favor of striking the testimony, saying he felt that Pettitte seemed “conflicted” in his various statements.

“He doesn’t know what Clemens said to him,” the judge said, before ordering briefings on the matter. Walton could rule at any time.